BioAid Meets Life

Couple of weeks ago me and my wife went to a hearing aid center for a free
consultation before, perhaps, buying a new hearing aid. The previous one has
been working just fine for five years or more and it has became unusable
lately. In the center they have run all the ususal tests, created an audiogram
and offered a couple variants to choose from. I was satisfied with the devices,
however I haven’t recognized any major difference from the one, that I already
had. I was hoping to manage with $600-$500, and I was shocked when they named
their price: even the cheapest of the devices was around $1000. We could afford
it, but I declined.

Being a person with inborn defect of the auditory nerve, I’m wearing a BTE
hearing aid all my life since the early childhood and I still remember the day,
when I put the thing on for the first time. For a boy, who haven’t been hearing
the sounds of footsteps on asphalt or the birds twittering, etc, it was a
marvelous to discover all those sounds for the first time. Later in life, when
I was wearing my fifth of sixth pair of hearing aids this wonderful piece of
technology was already taken for granted and I was actively using it in school,
university and later — in the workplace. Gradually, I started to recognize
quite a few shortcomings of modern hearing aids:

Most doctors would suggest you wear aids on both ears, since it is really
good at helping you to locate the sound and experience the stereo or 3D
hearing. Wearing two devices may be considered tempting if you don’t do
anything else with your ears like using a phone, headphones and participating
in all the different kinds of intense activities (sport?), when people may
unwillingly flick it off. It’s a physical inconvenience of having something
plugged into your ear that is not that simple to take off, but paradoxically
simple to drop. People using them day-to-day would understand, what I’m
talking about. Headphones and phone would also require you to take the aid
off first and don’t get me started on the horrible phone regime, which is
available in most modern aids. This was actually how I lost one of my aids: I
needed to use a phone, took it off and missed my pocket. Never saw that
device again.

Whistling. Yes, they are constantly whistling and it is a curse upon the
people with limited hearing. They whistle even more as the plastic ear mold
of the aid is wearing off, which means that ideally it should be replaced
every year. Whistling is produced by the mic and the speaker in the ear mold
since they are too close to each other and the feedback sound is being
produced. Ideally the ear mold should hermetically fit in the ear, to avoid
the feedback, but at times it sticks out anyway, and when it does — it’s
close to unbearable.

Close sourced software and hardware parts. This industry is controlled by a
bunch of electronics industry giants (Siemens, Phonak, etc) and they became
to some extent monopolistic in this market, since only they had the initial
resources to support research and production of hearing aids. Of course they
are laying out all the rules now, which leads us to the fourth and the worst
limitation of all.

The price. These devices are pricey as hell. It’s a mic, a little processor
and a speaker. Yeah, the size is super-small, but it doesn’t add up to
$1500-$2000 in my head, sorry. It’s just immensely overpriced. I’m not a
cheap guy, but I do have a problem when people feed me up with “magic” and
as I work in technology, I know that such claims are almost 100% marketing
and outright bullshit. They know that most of us — the hearing impaired
don’t have a choice and we’re forced to pay twice as much money for anything
they come up with. If you look for the last ten years — they are going round
in circles. Hearing aids haven’t seen any revolutionary improvement for
decades, compared with the booming technology market in consumer electronics
and it’s just sad.

Considering all the above, there is great demand for some open solution in the
market. Something you could thinker with yourself and use as a temporary or
permanent substitution for a commercial hearing aid. To achieve that, it should
be capable not only of recording, amplifying and reproducing the sound, but it
also should be smart enough to amplify only some frequency ranges, depending on
type and severity of the hearing damage. It would need some computational power
to process the sound. Ideally, it should also analyze the sound and get rid of
background noise, while normalizing the rest of it (making it quieter or louder
depending on the context). Modern smartphones are perfect candidates, since
they have everything we need in a hearing aid. I started looking for solutions
available as an iPhone app and stumbled upon BioAid.

BioAid is an app, implementing a full-featured hearing compensation algorithm,
developed by a team of scientists in the
university of Essex. They themselves stress on the fact, that this is not about
an iOS app, but the algorithm at the heart of it, which took years of research
and continues to evolve today.

Initially, the research was not concerned with hearing aids at all but with
the construction of computer models of how hearing works at a physiological
level in the auditory periphery.

However, the team has moved to working on hardware models and opted for mobile
phones, since commercial hearing aids are almost impossible or too expensive to
modify and require an agreement with the manufacturers, which is not that easy
to obtain. Smartphones have everything, that a hearing aid needs (a mic, a
processor and a speaker), they’re compact enough and modern smartphones have
sufficiently long battery life to perform on-the-fly sound processing almost
all day. In my case it was a godsend and I rushed to test the app in everyday
situations.

First thing I needed to do was to find the most suitable mode. For me it was
simple since I’ve done million audiograms and knew that my hearing lacks some
of the higher frequencies. After a quick scan I have found Gradual HF mode —
the one I recognized at once as it reminded me of how all my aids sounded. My
advice would be to start your scan with the first variants of every mode since
some of the modes may be too loud or high in frequency and it’s just unpleasant
to learn it the worst way. Surprisingly, finding the right mode is not a
problem at all. I was afraid the app would require audiograms and it would
complicate things. It’s definitely easier this way. Depending on the headphones
(they have different levels and may alter the sound a little bit) I was best
off with the 2nd and 3rd variants of Gradual HF mode.

I started testing the app in a park with lots of people walking, rolling and
skating around. Although it was quite a test to start with I was pretty
impressed with the results. It reminded me of times, when I put my first aid
on. I heard everything happening around quite distinctly. Frequencies were
altered in the right way. Sure iPhone headphones mic has its problems and I’m
still hoping to find a better one, but other than that, I had no problems at
all. It does reduce a little bit of background noise, depending on Gate value,
however I wouldn’t recommend setting it much higher than default settings as it
may cripple the other, more critical sounds. The problem with the standard
headphones mic boils down to missing out on sounds from behind or on the left
(if you have the mic on your right side) occasionally, but it’s not critical.
However, if you’re speaking with someone and the person is on the left — it may
work a little less precisely than usually. The mic is also quite sensitive to
wind and clothing rustle. Due to some lag you can’t use Bluetooth headphones,
though. This is an iPhone issue since people watching videos with Bluetooth
headphones sometimes notice that too.

Usually, I wear my hearing aid in office, since it is the only place, where
most of conversations are critical and may happen almost spontaneously. I was
also quite satisfied. I heard everything said on meetings, even better, than
with my previous aid, and decided to use BioAid at least temporarily at work.
The only problem I can imagine is people’s perception of wearing headphones all
the time. Some people assume that you’re listening to music. My office is quite
liberal and modern since it’s an IT company and a little Skype chat
announcement worked, I can imagine, however, it couldn’t always work this well.
Me personally, I find headphones more aesthetically tolerable than a BTE aid,
since people are almost constantly wearing headphones nowadays. Another problem
is that you may need to buy a battery extender case or enhance the battery life
of your iPhone in some other way. My battery is just enough to live through an
usual working day, avoiding, if possible other uses of the phone. I only listen
to some occasional music on my commute in the morning and after work. If I took
the phone off charger at 8 in the morning it is usually almost dead by 22 after
the full 8-hour day. Battery life is my biggest concern with the app so far. I
had thought of getting a separate iPod Touch player and run the app there as
professor Ray Meddis does in this video.

Other minor flaw is that algorithm is implemented in mono, though in theory,
stereo implementation is also possible. It is a problem since it may affect
your perception of the direction, the sound is coming from. Even if it was
processed as stereo, the iPhone standard headphones mic is mono, so the sound
is mono by default. Perhaps, stereo would be even worse as a battery drain, so
maybe it’s OK the way it is. It is specific to iPhone implementation only and
not the algorithm itself. Speaking about iPhone implementation, there are also
some minor issues that complicate the workflow: like the app stopping on phone
call and not resuming afterwards, or welcome screen appearing every time the
app is launched, but all of these are solvable.

Still, for now I’m not even thinking of getting back to commercial aids. I
have a very strong impression, that BioAid approach is the future of hearing
aids. Especially for people, who don’t have the hearing damage so severe, that
they require deep in-canal aids or even implants, which is majority of people
with hearing problems. Unloading the sound processing from the aid to a
smartphone or similar device (iPod Touch?) may be the right way especially
considering the fact, that going from nine to twelve channels adds up at least
a thousand dollars to the price of the commercial aid and iPhone has enough
computational power to process much more. Sure, there are still some problems,
but most of them are of the implementation and are going to be fixed sooner or
later.

Algorithm itself is entirely open-source, which means you can fork it on GitHub and create your own
version, addressing all of the issues described above, or providing support for
some other platform. If you’re a hearing impaired person and you’ve decided to
try BioAid for yourself, don’t forget to provide your
feedback to the research group, since it
may turn out very useful to them.

Update 14.11.2014: I’ve written another piece on BioAid in a
year’s time, where I’ve reexamined most of my earlier observations and
conclusions.